Wood grinding machine



March 3, v v L WENDSHUH 2,875,955 I woon GRINDiNG MACHINE Filed.'Sept. 13, 1956' 6 Sheets-Sheet 1 H. L. WENDSHUH 2,875,955

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H. L. WENDSHUH woon GRINDING MACHINE March 3, 1959 Filed Sept. 13 1956 mil/11W 6 Shets-Sheet 4 MatchB, 1959 H.- L. WENDSHUH WOOD GRINDING MACHINE Filed Se pt'. 13, 1956- 6 Sheets-Sheet 5 v 6 0 \o 0 Q v March 3, 1959 HIL. WENDS'HUH woon GRINDING MACHINE 6 shee t s s he et' e 7 Filed Sept. 13 1956 64 Z? Z Z Z oe w United States Patent O Appleton Machine Company, a corporation of Wiscousin Application September 13, 1956, Serial No. 609,581

4 Claims. (Cl. 241-46) This invention relates to a wood grinding machine comprising a cylindrical housing, a feed ring rotatably mounted in said housing, and a grinding stone eccentrically mounted within said feed ring and adapted to cooperate therewith to grind logs.

The feed ring of the present invention is cylindrical and its outer edge portion is rigidly secured to a ring gear which is rotated slowly by a pinion. Two parallel series of shoes of plastic material, for example a phenolformaldehyde condensation product such as is presently available under the trademarks Micarta and Bakelite, or other suitable material, are mounted on the outer surface of the feed ring. The shoes extend around the entire circumference of the feed ring and form substantially continuous bearing surfaces for the feed ring. The bearing surfaces are lubricated automatically as the feed ring is rotated. The shoes may be removed and replaced individually, as they become worn, without dismantling the machine.

The bottom case of the housing has a pair of grooves into which the bearing shoes fit to prevent lateral displacement of the lower portion of the feed ring. The upper portion of the feed ring is stabilized either by a continuation of the grooves or by one or more pairs of guide rollers rotating about an axis at right angles to the axis of rotation of the feed ring.

The feed ring is rotated in the same direction as the grinding stone to force the logs toward the stone, thereby obtaining the grinding action required. The inner surface of the feed ring is roughened to cooperate with the peripheral surface of the grinding stone to provide efficient grinding of the wood.

-The bottom case of the housing is provided with a discharge outlet for the ground'wood and water at each side of the machine. Perforated bafile plates at opposite sides of the feed ring permit the flow of the ground wood and water into the discharge chute without permitting shims to pass through. The feed ring is also provided with openings leading directly to the discharge chute. v

A series of jet nozzles aligned with the openings in the feed ring serve to flush out the openings and prevent them from becoming clogged. A pair of deckle straps secured to the housing cover the gap between the housing and the edge of the feed ring to prevent the water from flowing past the bearings and into the gearing. If the deckle straps should allow passage of water, the bearings would prevent such water from reaching the gears.

The structure by means of which the above and other advantages are attained will be described in detail in the following specification, taken in conjunction with the accompanying drawings, showing two preferred illustrative embodiments of the invention, in which:

Figure l'is a side elevational view of a machine embodying the invention;

Fig. 2 is an end elevational view of themachine;

2,875,955 Patented Mar. 3, 1959 ice Fig. 3 is a cross sectional view, taken along the line 3-3 of Fig. 1; Y

Fig. 4 is an end elevational view through the machine of Fig. 1, with parts broken away to illustrate the interior structure;

Fig. 5 is a vertical sectional view through a modified embodiment of the machine in which the bearing shoes cooperate with grooves around the entire inner circumference of the housing to guide the feed ring and prevent lateral displacement thereof;

Fig. 6 is a fragmentary cross sectional view, taken along the line 6-6 of Fig. 8;

Fig. 7 is a cross sectional view, taken along the line 7-7 of Fig. 3;

Fig. 8 is a cross sectional view, taken along the line 8-8 of Fig. 3;

Fig. 9 is a cross sectional view, taken along the line 9-9 of Fig. 3;

Fig. 10 is a fragmentary cross sectional view showing one of the grease pockets for lubricating the bearing shoes;

Fig. 11 is a detail perspective view of one of the bearing shoes; and

Fig. 12 is a fragmentary elevational view, showing the means for securing'the bearing shoes to the feed ring.

Referring to the drawings, the reference numeral 2 indicates a base having a pair of parallel fiat surfaces 3 upon which a cylindrical housing 4 is supported. Housing 4 is made in two parts, an upper case 5 and a bottom case 6 having abutting flanges 7 secured together in any suitable manner'after the rest of the machine is assembled. Surfaces 3 extend beyond each end of the housing and are separated by a channel 8 open at its top to receive a bulged wall portion 9 projecting outwardly from the center portion of the housing around its entire periphery.

On opposite sides of the bulge 9, the housing has a pair of flat surfaces 10 in engagement with the flat surfaces 3. A screw 11 journalled in a bearing in standard 12, mounted on one end of the base, is provided with a lever 13, by which it may be turned to move the housing 4 on base 2. This movement of the housing is for the purpose of compensatingfor the wear on the grinding stone, hereinafter described, and is limited in extent.

Two standards 14 at opposite sides of housing 4 support bearings 15 in alignment with each other along an axis eccentric to the center of housing 4. A shaft 16 journalled in bearings 15 extends through openings provided therefor in the side walls 17 of housing 4. Shaft 16 is rotated by a motor (not shown). A grinding stone 18 is'mounted on shaft 16 to rotate therewith. The grinding stone is smaller in circumference than the interior ofhousing 4, and its axis is below the center of housing 4 and closer to one end of the housing than to the other, as shown in Figs. 7, 8 and 9.

The width of grinding stone 18 is less than the width of the housing 4, as shown in Fig. 3. The grinding stone is centered, relative to the housing, by a pair of collars 19 which prevent any lateral movement of the grinding stone on shaft 16. A bafiie plate 20 is held adjacent each side of the grinding stone by a plurality of rods 21, each threaded through an aperture in wall 17 and engaging a boss 22 projecting outwardly from the baffie plate. A nut 23, threaded on each rod 21,

is tightened against wall 17 to hold the bafile plate ad-. jacent the side of grinding stone 18 with just enough. clearance to allow the grinding stone to rotate freely.w

Both baffle plates 20 are alike and the description of one will apply to the other as well. As shown in Figs.

I 7, 8 and 9, the bafile plate extends from the bottom of housing 4 to a point above the axis of the grinding;

stone. Gne edge of'the baffle plate is curved to conform to the configuration of the inner-surface of housing 4. The other edge of the baffle plate is curved to conform generally to the peripheral edge of the grinding stone which it overlaps slightly. A plurality of perforations 24 extend through the baffle plate to allow ground wood and water to pass therethrough into the space between the battle plate and the adjacent side wall 17 of the housing. The space between the baffle plate and side wall 17 forms partof a discharge chute 25 which extends from one end of the housing.

A ring gear 26, having teeth 27 on its outer surface, is rotatably mounted within the peripheral bulge 9 of housing 4. Housing 4 is provided with an opening 28 (Fig. 7) aligned with gear 26. A gear'29, mounted on a shaft 30 adjacent opening .28 projects through the opening into. mesh with gear teeth 27. A motor 31 mounted on the outside of housing 4 rotates shaft 30 and, through it and gear 29,'the ring gear 26. A cover member 32 is provided on the outsideof housing 4 to serve as a housing for gear 29. Ring gear 26 is T-shaped in cross-section and has a centrally located flange 33 extending inwardly therefrom.

A feed ring 34, mounted within housing 4 is secured to flange 33 and rotates with the ring gear. The feed ring comprises two sections 35 and 36 (Fig. 3) for convenience of assembly. The inner edges of both sections are oifset, as indicated at 37 to facilitate alignment of the two sections, and each section is provided with a peripheral flange 38 set back from its inner edge a distance equal to half the thickness of flange 33. Flanges 38 fit on opposite sides of flange 33, and all three flanges are provided with registering apertures to receive bolts 39. by means of which the feed ring sections are both secured to each other and to the ring gear. Both sections of the feed ring are alike, so only one section will be described, the same reference numerals being applied to both sections.

Bearing shoes 40 are secured to the periphery of feed ring 34 in end to end relationship to furnish a continuous bearing surface. The shoes may be of plastic, for example, it may be a phenol-formaldehyde resinous condensation product such as that sold under the trademark Ryertex or the trademark Insurok, or any other suitable material. Each shoe is in the form of a generally rectangular block curved slightly in its longitudinal direction to fit against the outer surface of the feed ring which is grooved, as indicated at 41, Fig. 10, to provide a seat for the shoes. Each shoe is provided with a countersunk aperture 42 adjacent each end and is secured to the feed ring by screws 43 which extend through the aperture 42 into a threaded recess 44 in the feed ring. If any shoe becomes worn it may be removed and replaced without disturbing the adjacent shoes. Each shoe 40 is recessed adjacent each end, asindicated at 45, Fig. 11, so that when the shoes are secured to the feedring in end to end relationship the notches form. a reces s 46.1 Housing 4 is recessed to form lubrication pockets 47 aligned'with the bearing shoes 40. A grease pump (not shown) has a nozzle 48 fitting into an opening 49 leading into each pocket 47 by means of which lubricating material is forced into the pocket under pressure to keep the pocket always filled -with a suitable lubricant. As the shoes rotate with the feed ring, each recess- 46 picks up some of the. lubricant which serves to lubricate the bearing surface. Two lubrication pockets are shown in Fig. 9, but it Willbe understood that the number may be varied, as desired.

The bottom case 6 of housing 4 is provided with a circumferential groove 50 on its inner surface which serves as a guide for bearing shoes 40, which fit in said grooves, during their movement around the lower half of the housing. The groovesSt) cooperate with shoes The upper half of the feed ring is stabilized by rollers 51 which abut the lateral edges of the feed ring and are rotatable about an axis perpendicular to the axis of rotation of the feed ring. Each roller 51 has a shaft 52 which projects through an opening 52 in the housing. A support 51 holds each roller 51 against vertical displacement, and a set screw 53 extending through a bracket 54 positioned adjacent the outer surface of housing 4, exerts lateral pressure against each support 51' to maintain roller 51 in juxtaposition with the side of feed ring 26 with a suitable lateral pressure.

Housing 4 is provided with an opening 56 in the upper portion of its side wall 17 for loading wood, preferably in the form of logs having a length slightly less than the Width of the grinding stone 18, into the machine. Any suitable door may be mounted on the housing to serve as a closure for opening 56. The Water necessary for the grinding operation is fed into the machine by a perforated pipe 57 extending transversely of the housing above the grinding stone. The inner surface of feed ring 34 is provided with transverse and circumferential ribs 58 projecting inwardly therefrom.

The outer edges and the outer periphery of feed ring 34 are formed, as indicated at 59, Figs. 3 and 6, to provide a space 60 between the feed ring and the housing 4. This space 60 forms part of the discharge chute 25. The feed ring is provided with three transversely spaced series of openings 61, 62 and 63. The openings 61, 62 and 63 extend through the feed ring an-gularly so that each opening leads to the space 60. The stock, in the form of a mixture of finely ground wood and water, that is discharged through these openings at the bottom of the feed ring flows into the space 60.

In order to prevent the openings 61, 62'and 63 from becoming clogged, a Water hose 64, provided with three jet nozzles 65, 66 and 67, is mounted on the outside of the housing. Each nozzle is aligned angularly with one of the openings 61, 62 or 63, and is positioned close to the feed ring so that water from each nozzle flushes out the openings of one of the series of openings.

The stock is prevented from flowing into engagement with either the bearing shoes 40 or the ring gear 26 by means of a deckle strap 68 which extends around the bottom case of housing 4 to cover the gap between the housing and the edge of feed ring 34 adjacent groove 41. One end of the deckle strap is rigidly secured to a flange 69 on the upper half of housing 4, as indicated at 70, Fig. 8, and the other end is secured to a similar flange 71 at the opposite side of the housing, as indicated at 72. The securement at 72 is adjustable so that the deckle strap may be kept taut in order to form an effective water seal. If any water does pass the deckle strap it will be stopped by the bearing shoes and will do no real damage since it cannot reach the gear 26'.

A doctor blade 73 is pivotally mounted in housing 4,

as indicated at 74, with its bevelled end 75 adjacent the periphery of grinding stone 18. The doctor blade extends across the entire width of the housing and removes any wood shims that might otherwise stick to the grinding stone and impair its efliciency. These shims are generally repelled by the stone through centrifugal force. However, should they have a tendency to adhere to the stone, the doctor acts as a stripper, causing the shims to be moved outwardly against the ribbed surface of feed ring 34.

A plate 76 curved to conform to the curvature of the feed ring extends across the entire Width. of the housing and has its outer edges secured to side wall 17 of thehousing, as indicated at 77. The lower edge of plate 76 ispositioned just above the top of doctor blade 73 so that shims thrown outwardly from the doctor blade are caught between the plate 76 and the feed ring; so that they cannot drop until they areover the feed side of the machine.

The operation of the machine will now be described. The logs are loaded into the machine through opening 56 and water is fed through pipe 57. The grinding stone and feed ring are rotated in the same direction, i. e. clockwise as viewed in Figs. 7 and 8, but at different speeds. The internal ribs 58 on the feed ring engage the logs and move them toward the underside of the grinding stone. Since the logs cannot move backwards, they remain in the grinding zone between the inner surface of the feed ring and the peripheral surface of the grinding stone until they are substantially completely ground. Only the shims small enough to pass through the small clearance between the feed ring and the grinding stone pass by the doctor. These shims are thrown from the grinding stone against the ribbed surface of feed ring by centrifugal force. The shims are moved by the ribs 58 across the upper half of the housing and then mixed with the logs introduced through the opening 56.

The stock, which comprises approximately 2% ground wood and 98% water, flows through openings 61, 62 and 63 into space 60. Additional stock flows through perforations 24 in battle plate 20 into the discharge chute 25.

The bearings 15 in which the shaft of the grinding stone is mounted are stationary. Accordingly, as the grinding stone becomes worn the space between its peripheral surface and the inner surface of the feed ring increases. In order to prevent too great an increase in the clearance between the grinding stone and the feed ring the screw 11 is turned to move the housing to the right, as seen in Figs. 7 and 8, to restore the clearance space to the desired dimension. The housing is moved to the left when the grinding stone is to be replaced by a new stone. The sectional structure of the housing permits the side walls 17 to be removed for removal or insertion of the grinding stone, and the upper case 5 of the housing to be removed for removal or insertion of any of the bearing shoes 40.

The modified embodiment of the invention shown in Fig. 5 is the same as that previously described except that the upper case 5 of housing 4 is provided with a groove 50 which cooperates with groove 50 in the bottom case 6 to form a continuous guide for the bearing shoes 40 extending circumferentially around the entire inner surface of the housing. In this embodiment the rollers 51 are eliminated. The rest of the structure of Fig. 5 is identical with that of the preferred embodiment and therefore will not be specifically described, the same reference numerals being used to indicate the identical structure.

While I have described two preferred embodiments of my invention in considerable detail, it will be understood that the description is intended to be illustrative, rather than restrictive, as many details may be modified or changed without departing from the spirit or scope of my invention. Accordingly, I do not desire to be restricted to the exact details of construction described.

I claim:

1. A wood grinding machine comprising a housing adapted to be loaded with logs and water, a feed ring rotatably mounted in said housing, a grinding stone eccentrically and rotatably mounted within said feed ring to form a grinding zone between said grinding stone and said feed ring, means for rotating said feed ring and grinding stone to grind the logs in said housing into stock comprising a mixture of ground wood and water, a discharge chute extending from said housing for discharge of stock therefrom, a plurality of laterally spaced series of openings arranged round the periphery of said feed ring and extending directly through said feed ring at difierent angles whereby each of said openings at the lower portion of said feed ring communicate directly from within the feed ring to said discharge chute for flowing stock from said grinding zone into said discharge chute, a Water hose mounted on said housing and a plurality of water jets connected to said hose at different angles, said housing having an aperture above its lowermost portion to receive each of said jets, each of said jets being aligned with the openings of one of said series of openings for flushing said openings above the lowermost portion of said feed ring to prevent interference with the subsequent flow of said stock therethrough.

2. In a wood grinding machine having a housing, and a feed ring, a series of individual bearing shoes, said shoes being mounted in end to end relationship on the outer surface of said feed ring and bearing against the inner surface of said housing to form a continuous bearing surface between said feed ring and said housing, each of said shoes being notched at both ends to form recesses to receive lubricating material, a lubrication pocket recessed from the inner surface of said housing in alignment with said bearing shoes, and means for forcing lubricating material into said pocket under pressure, whereby lubricating material is supplied to the recesses at the ends of said bearing shoes.

3. A wood grinding machine comprising a housing adapted to be loaded with logs and water, a feed ring rotatably mounted in said housing, a grinding stone eccentrically and rotatably mounted within said feed ring to form a grinding zone between said grinding stone and said feed ring, means for rotating said feed ring and grinding stone to grind the logs in said housing into stock comprising a mixture of ground wood and water, a discharge chute extending from said housing for discharge of stock therefrom, a plurality of laterally spaced series of openings arranged around the periphery of said feed ring and extending directly through said feed ring whereby each of said openings at the lower portion of said feed ring communicate directly from within the feed ring to said discharge chute for flowing stock from said grinding zone into said discharge chute, a water hose mounted on said housing and a plurality of water jets connected to said hose, said housing having an aperture above its lowermost portion to receive each of said jets, each of said jets being aligned with the openings of one of said series of openings for flushing said openings above the lowermost portion of said feed ring to prevent interference with the subsequent flow of said stock therethrough.

4. In a wood grinding machine having a housing and a feed ring, a circumferential groove in said feed ring, a series of individual bearing shoes, said shoes being mounted in end to end relationship in said groove in the outer surface of said feed ring and bearing against the inner surface of said housing to form a continuous bearing surface between said feed ring and said housing, each of said shoes being notched at both ends to form recesses to receive lubricating material, a lubrication pocket recessed from the inner surface of said housing in alignment with said bearing shoes, means for forcing lubricating material into said pocket under pressure, whereby lubricating material is supplied to the recesses at the ends of said bearing shoes, and a circumferential groove in the inner surface of said housing, said groove fitting against the longitudinal edges of said bearing shoes to form a guide for rotation of said feed ring.

References Cited in the file of this patent UNITED STATES PATENTS 1,448,774 Stehlin Mar. 20, 1923 1,854,570 West Apr. 19, 1932 1,876,064 Lang Sept. 6, 1932 2,282,887 Roberts May 12, 1942 2,406,904 Roberts Sept. 3, 1946 2,642,231 Illig June 16, 1953 2,748,667 Grieb June 5, 1956 

